A G31 struggles with older games. For example, Guild Wars is barely playable at 1440x900 (e.g. 21FPS).
If you won't be playing any games or watching 1080p, it doesn't matter. If you will do either of these, the HD3300 on the 790GX is the strongest IGP right now. An AMD 550BE or 720BE will provide decent performance.
If you believe you need integrated graphics because of a weak PSU that you are unable or unwilling to replace, even a 4650 will blow past any of the IGPs, and needs no aux power.